Thread-looping mechanism for stitching machines



March 9 1926;

L. J. DU MAIS ET AL THREAD LQCPING MECHANISM FOR STITCHING MACHINES 2Sheefs-Sheet 1 Filed Jan. 22, 1924 [wafers Lea I514 [@115 March 9 1926.y

L. J. DU MAIS ET AL THREAD LOOPING MECHANISM FOR STITCHING MACHINESFiled Jan. 22, 1924 2 Sheets-Sheet 2 Patented Mar- 9, 1926.

UNITED "srAIEs mesa Lno J. DU MAIS Ann FLOYD n. MINER, or orr'roaeo,ILLInoIs, assrenons '10 cI-II- CAGO SHOE MACHINERY COMPANY, or oIIIceso,ILLINoIs, A con ronarron or ILLINOIS.

THREAD-LOOPING IvEECI-IANISM FOR STITGHING MACHINES.

Application filed January 22, 1924. Serial No. 687,862.

To all whom it may 0mm."

Be it known that we, LEO J. DU MAIs and FLOYD E. MINER, citizens of theUnlted States, and residents of Chicago, in the.

i of looping the thread in the path of the needle of a stitching machineand particularly, of such a machine used for stitch ng leather, and itconsists in the features and elements and their combination hereinafterdescribed, shown in the drawings and pointed out by the claim.

In the drawings: 7

Figure 1 is a side view of a stitching machine taken transaxiallyof thedriving shaft and in a plane parallel to the path of the needle andcertain other parts associated therewith which are directly concerned inand with the present invention.

Fig. 2 is a View takenas indicated at the line 22 on Fig. 1.

Fig. 3 is a fragmental view in plan, on an exaggerated scale of thethread looper, the thread hook and the needle.

Fig. 4 is a developed view of one of cams.

Fig.5 is a diagrammatic view in plan of the thread looper arm andindicating the path of travel of the thread looper eye.

It will be understood that in Figs. 1 and 2 of the drawings, only suchparts as are concerned with the control of the lower one of a two-threadstitching machine are shown, omitting other parts which cooperatetherewith in a manner well understood in the art, but which are not heresought to be claimed. The structure herewith shown comprises a basemember 10, a bracket arm 11. and the two standards 1212 which aresuitably secured to the upper side of the base member. A shaft 13 isjournaled in the bracket 11 and is driven in any suitable manner nothere shown. Mounted on the shaft 13 and keyed thereto for rotationtherewith is a compound cam 14 which rothe tates in a counter-clockwisedirection as indicated by the drawing.

The cam 14 has several sets of grooves, one set being cut or formed inthe periphery thereof at 15, another in one of its lateral faces at16,21 third in the same facebut nearer the center thereof at 17, and afourth in the opposite face thereof at 18, shown in dotted lines, thelatter road or groove governing the travel. of a thread engaging needlewhich operates in a manner quite common to all machines, this cam roadonly being shown here to indicate the possibility of forming all thecontrolling roads or grooves for. the said moving parts in a single camwheel with the advantage of lightening the power to operate the machineand with the furtherv advantage of insuring that their predeterminedrelative position will remain unchanged, it being conceivable thatseveral separate cams could and might, through inadvertence, becomederanged.

The first two mentioned cam roads 15 andu16 control the action of athread looping device 19,-while the-cam road 1'? controls the action ofa thread hook indicated at 20.

The thread looper 19 is mounted for traveling in a horizontal plane andhas imparted thereto differential movement in a peculiar three-corneredorbit 21, (see Fig. 5) because of its being secured at the free end 22of a bar 23 which is mounted for reciprocation in guides 25-25; theguides themselves be ingmoved laterally through their connections 2626to a bar 27 which is fulcri'lmed at 28 to the base plate 10. Acam-engaging roller 29 is rigidly secured to the bar 27 some distancefrom the fulcrum 28 and motion imp arted by the cam road15 in theperiphery of the wheel 14:. This cam road 15 it will be observed isformed to cause the thread loopcr to travel laterally, toward and fromthe thread hook 20. During this lateral movement caused by the bar 27being swung about its fulcrum 28, a second movement is imparted theretoby the reciprocation of the bar 23.

.The bar 23 which, as stated, is mounted in the guides 2525 hasconnection, through a swivel joint 30, to a lever 31. This lever 31 isfulcrumed at 32 in the bracket 11. A conveniently arranged arm 32integral with the lever 31 carries a roller 33 which engages the camroad 16; the total length of the lever arm 31 and the position orlocation of the roller 33 thereon provides the necessary longitudinalmovement to the bar 23 by virtue ,of the shape or formation of the road16 with which the roller 33 cooperates.

Further elucidating, it may be here stated that the several criticalrelative positions of these two last mentioned cam roads, and

16 with their cooperating rollers 29 and 33.

Fig.1, the roller 29 occupies the position tion A marked A. The roller33 occupies ,the posi- The thread looper will then be in theposition orpoint of. the angle (see Fig. indicated at A; upon 'rotation ot thewheel 14 in the direction of the arrow, the next indicated position willbe when the roller 29 is at B and the roller is at B and so on throughthe cycle, the thread looper will then travel, as indicated in Fig. 5from A to B; dwell from B to C; travel from C to D; dwell from Dto E;travel from E to F; travel from F to Gr; and back to H. r Ononeof thestandards 12 is mounted a rock-shaft 10 which is actuated by theiarln 41having a roller 42 travelingin the road 17 ofthe wheel 14. The rockshaft40 has mounted upon it for swinging, a lever; 43 whose free end engagesand operates 'the thread hook 20, which is mounted for longitudinaltravel toward and from the path of the thread, said thread beingconveyed in its path by the thread looper 19. It will be clearlyunderstood by reference to Fig. 1 of the drawing that the thread hook 20is mounted on the inner surface of the upward.- ly and forwardlyextended portion of one of the standards 12 in an upwardlyand rearwardlyinclinedguide-way and that the upper end of the lever 4L3 looselyengages a re. cess in the lower surface of said hook, to the end, whenthe lever 43 is rocked, the thread hook 520 will be slid backand forthin its inclined guide-way.

' During the interval that the hook 20 is looper then tra 'eling acrossthe needle, passing from the position E to F, and finally to Gr, pullingthetht'eadtaut.

It is to be understood that the needle 50 in descending, enters the workthrough a hole in the work which wasproduced by ana'wl ($0. a fragmentof which is shown in Fig.

This awl is mounted upon a quadrant shown at 6'1 and operating, from,the under side of the work plate 5a.- The .awl qnadrant fil-is operatedby a segment 62 and controlled by the canrroad 18 on the wheel 14.

"l/Vhile the thread is so engaged yby the hook 20, the needle 50 is.causedto recede and as its barb 55 engages the thread for drawing itthrough the slot 5 3 and also the work, the hook 20' 'is it againadvanced ready for the next stitch. The thread so drawn up through thework by the needle, forms a loop for the receptiomof a bobbin inacustomary amt Well known manner, not here SllOWlTOI claimed.

- litavingv-thus ifullyfdescribed our invention, what we claim as newanddestre to secure by Letters Patent is: 1 i. 1

In a stitching machine, thecomhination with a ha'rhed .needle and theWork+plate, said work-plate havingla slot forthepassage of the needletherethrough, ;Of a thread loopermovable in a horizontal plane, and athread hookniovable in anllupwardly inclined plane with respect to saidhorizontal plane, said looper and the said thread hook cooperating :topositively. engage the thread uponithe barbf of the needle, means foroper. ating the thread looper, said means including a cam-groove wheel,rollers engaging said grooves, one of said rollers being mountedzuponiavertically mountedlever and the other oi saidlrollers being mounted upona longitudinally swinging ]ever,both of said mounted for pivotalmovementin a vertical plane and operatively connected to the thread-hook, andaroller carried by said arm.

and engaging one of the grooves of said wheel.

LEO J. DU Mars; rnorn Mirna

